Electric clock mechanism



Nov. 10, 1931. A. F. PooLE 3 3 ELECTRIC CLOCK MECHANISM Filed April 4.1927 :5 sheets-sheet 1 Nov. 10, 1931. AF, POOLE 1,831,260

I ELECTRIC CLGCK MECHANISM Filed April 4, 1927 3 Sheets-Sheet 2 Nov. 10,1931.

A. F. POOLE ELECTRIC CLOCK MECHANISM Filed April 4, 1927 3 Sheets-SheetI5 Ina/67%;

' AR 'THUB driving Patented N. 10, 1931 UNITED STATES PATENT OFFICE 1room, or makes. new YORK; ,essronoa ro roomaumirnc'r'omno 00., INC., 01-ITHAQA, NEW YORK, A CORPORATION OFNE'W YORK ELECTRIC GLOOK MECHANISMApplication filed April 4,

This invention relates to electric clocks, and has for its object theprovision of a sim; ple and accurate clock driving mechanism, in whichthe usual clock-springs and weights are eliminated; and to provide amethod of clockwork by which the electric power 1s applied to the timedeterminin element in small periodic impulses of de ite force, withoutthe necessity of,storing up mechanical ener for any considerable lengthof time. ther objects .of the invention are to relieve the esca'pemntwheel of' the load of driving the pendulum; to'maintain the strength ofthe periodic im ulses substantially inde endent of the or inaryvariations in the riving force, to prevent damage to the es'capementthrough careless handllng of the endulum; and various other objects asw1ll become apparent, all with a view to producing a simple, practicaland accurate clock mechanism.

In the drawings forming part of this specification and illustrating oneembodiment of the invention,

.1 is a side elevation of an electric clock mechanism, showing thegeneral relations of parts in a typical construction.

Fig. 2 is a rear elevation of the clock actuating mechanism, taken onthe line 2-2 of Fig. 1, looking in the direction of the arrows, showingthe relation of the parts at the moment the electric contact is broken,and the driving impulse is being delivered to the pendulum.

Fig. 3 is a somewhat similar elevation of the clock actuating mechanismas viewed from the rear, illustrating the relation of the parts at themoment when the electric contact is being made, and before the actuationo the driving mechanism.

Fig. 4 is a detail view showing one form of the driving spring,yieldable crutch and pallet holding mechanism. i

Fig. 5' is a cross-sectipn of a second crutch mechanism, the sectionbeing taken on the line 5 5 of Fig. 2, looking in the direction ofthe'arrows.

Fig. 6 is a detail side elevation of the crutch mechanism, one form ofndulum support,

1927. Serial No. 180,830.

and 4 is located an iron armature 5, which is' pivotally mounted at thepoint 6, so that it may oscillate. A cam 7 is clamped to the armature 5by means of the screw 8-, so as to oscillate with the armature, and thisarmature member 5, 7, 8, is unbalanced relative to the pivot 6, so thatwhen the solenoids 2, 2', are not energized the armature will drop downto the position shown in Fig. 3 of the drawings.

Coacting with the'cam 7 is a camrfollower consisting of a lever 10provided with a roller on its end to engage the cam 7, which is designedto give a quick positive stroke. The lever 10 by wa of illustration isshown in the. form of a ell crank pivoted at 11 and having an extensionfinger 12the weight of this bell crank being partially supported by thespring 13. It will become apparent to those skilled in the art as thedescription proceeds that the particular form of this lever 10-12 isimmaterial and the shape shown in the drawings is only for the purposesof illustration. The function of the arts described'is to transmitsuitable impu ses from the solenoids 2, 2 to the impulse controllingelement 14, which delivers the measured impulse to the pendulum or othertime determining device.

The power delivered by the cam 7, while more than ample to drive a clockmechanis isnot in a form suitable for precise regu ayieldable palletsand drlv'e spring, giving a counter weight 16 or other means for re- Nas shown in Figure 2, for reasonsthat will turning it to position. Atthe 0 erative or driving end 0 the lever 14 is a pm 17, preferably ajewel, which is adapted to engage the spring 18 when the lever 14 isactuatedin which case the lever is swung to a position substantially atright angles to the spring 18,

be described.

. The spring 18 is attached to the pendulum or time determiningmechanism, and swings as a part thereof, so that it'is periodicallybrought to a position where the pin 17 may engage it. This spring 18 isthe actual driving element which operates the pendulum, by virtue of themechanical energy stored in the spring 18 by the action of the impulseelement 14. In the preferred form the time determining element is of thependulum typethough a balance wheel or other equivalent device might beused-and consists of a pendulum bob 19 carried on the rod 20 suspendedfrom the flat spring 21. The rod 20 is driven thru a crutch 22 mountedon the pivot 23. The crutch 22 is driven thru a second crutch 24, 25,having a special construction as will be later described, and a part ofthis second crutch 25 has attached to it the spring member 18, thruwhich the driving impulses are received.

The spring member 18 preferably consists of a flat spring, and itstension and position is adjusted by the adjusting screw 26 mounted inthe rigid arm 27, which is secured to the crutch member 25. Thus thespring 18, arm 27, as well as the crutches and pendulum proper swing aspart of the pendulum element. The spring 18 carries a contact button 30which is adaptedto make contact with the adjustable electric contactscrew 31 near the end of a swing, completing a circuit which energizesthe electro-magnetic portion of the mechanism. The contact screw 31 isinsulated from the frame by theinsulation 32, and the electric circuit,when closed, may be traced from one. terminal of the battery B thru thesolenoids 2 and 2, then thru the ,wire 33 to the contact screw 31,contact button 30 and thru the spring 18 to the other terminal of thebattery Bthe spring 18 and one terminal of the battery being grounded tothe frame.

The operation of the portion of the mechanism that delivers periodicimpulses to the pendulum elements will now be described,

after which the manner of driving the clock will b shown.

As t e pendulum swings to the right, the contact button 30 in the spring18 meets the contact screw 31 and closes the electric circuit described.The electro-magnets 4 and that the pin 17 engages the spring 18 andforces it slightly back, breaking the electric.

circuit at the contact button 30. This deenergizes the electro-magnets 4and 4 and the armature 5, and the cam and levers 7, 10, 12, fall back totheir original position. The element 14, however, does not immediatelyfall, but is held in the position shown in Fig. 2 by the pressure of thespring 18, owing to the, fact that the impulse'element 14 is thensubstantially at right angles to the driving spring 18. The impulse isgiven the driving spring 18 by the extra flexure given it when the pin17 swings down against it, thus storing up energy in the spring tooperate the pendulum. As the pendulum swings back, it absorbs thisdriving energy, and as it progresses the screw 26 on the arm 27 picks upthe spring 18 again, and carries the spring 18 away from'the pin 17,whereupon the element 14 returns to its former position.

The increment of energy is stored in the spring 18 at each vibrationof'the pendulumor possibly at alternate vibrations but it is notnecessary to store energy up for any considerable number of vibrations,as in previous constructions. It will be obvious to those skilled in theart that in place of the armature 5 being retracted by gravity, themagnetic elements may be arranged to rock the armature back and forth,so that alternate vibrations of the pendulum will receive the drivingimpulse. But in either event the apparatus is characterized by the factthat as soon as the motor element is retracted its driving stroke ensues.on the next vibration of the pendulum, thus reducing to a minimum theperiod during which stored mechanical energy is retained.

The action of the impulse element 14 in relation to the driving spring18 has'several advantages, in addition to retaining itself in workingposition thru friction as described. It will be understood that accuratetime keeping is largely dependent on delivering driving impulses ofuniform strength and intensity.' To do this, various difiiculties mustbe overcome, as for example, the power of the original electro-magneticforce will vary somewhat as the battery weakens; the initial power isrelatively large and not suitable for regulation; and the mechanism mustbe such that slight variations in the parts. such as occur in commercialproduction. will not seriously affect the uniformity of the operation ofthe time determining element.

In the present invention the power is trans mitted by bending the spring18 when swinging the pin 17 thru an are which in its later portionapproaches tangency to the spring. It will be seen, therefore, thatslight variations in the length of this arc. such as might occur thruvariations in the strength of the electric power, or slight. variationsin the mechanical parts, thru wear or otherwise,

- ment wheel, and the escapement wheel drives 7 nunaoo This method oftransmitting repeated small and controlled increments of energy directlto a driving s ring which oscillates with t e endulum a so makespossible a method 0 operatin a clock mechanism which has certain avantages in simplicity and accuracy. It will be recalled that in theordinary clock the power drives the escapethe pendulum-the pressure ofthe escapement teeth giving a slight impulse to the pendulum at eachswing. In the present invention, on the contrary the power is at in thruthe pendulum and taken out t ru a crown wheel 40, for example, orequivalent gear, in place of the ordinary escapementthe crown wheelbeing fed along tooth by tooth thru the power supplied to it by thependulum. The driving friction in the clockwork is thus made light anduniform, with a resultant increase in accuracy and durability.

The crown wheel 40 is rotated by the alternate engagement of the pallets41 and 42 with the teeth or pins of the crown wheel as the pendulumswings to and fro. These pallets have faces properly inclined to feedthe crown wheel 40 around one tooth at a time. The crown wheel 40 turnsthe hands 43 and 44 thru the reduction gearing 45, 46, etc. of ordinaryclockwork. In order to prevent possible damage to the teeth of the crownwheel 40 which might occur thru careless handling if the pallets 41 and42 were rigidly secured to the pendulum. the pallets are arranged sothat theymay yield against a spring in case of excessive stress. Thepallet 41 is attached to a member 51 which carries the pin 24, and thepallet 42 is attached to a member 50 which carries the pin 25-themembers50 and 51'being mounted on the pivot 23 and held together by thetension of the spring 52, so that the pins 24 and 25 form a crutch,connecting to the ordinarv crutch 22 and pendulum 19. The spring 52 issufficiently strong to hold the crutch 24, 25 together in all normaloperation. so that the pallets 41 and 42 normally act as though theywere rigid with the pendulum: but in case of an excessive accidentalstress the pallets will yield before damaging atooth.

While I have in the foregoing disclosed my invention and described it byWay of illustration in a preferred embodiment, it is subject of courseto various modifications as will be evident to those skilled in the art.The particular arrangements, shape and proortions of the parts will varyto accommoat-e various forms of clocks, and the particular form ofelectric circuit is immaterial, provided it is periodically varied.

While I have explained and described my invention by certain a ificexamples, it will be understood that t ese are on y by way ofillustration, and that the apparatus is susceptible to variousmodificatlons and adaptations as will be a parent to those skilled inthe art, without d zeparting from the scope of the invention, which isspecified in the following claims.

Claims:

1. In a time keeping mechanism, the combination of a time determiningelement having a periodic motion, a drivlng spring attached thereto, animpulse member adapted to be swung in an arc terminating substantiallytangent to said spring, whereby the spring may be flexed and powerapplied to the time determining element, an electric contact operated bythe motion of the time determining element, and an electrically operatedmechanism controlled by said contact whereby the impulse member isdriven to flex the spring, the electric contact being opened by theaction of the impulse member on the sprin 2. In a time keepingmechanism, the combination of a time determining element having aperiodic motion, a sprin attached thereto so as to oscillate therewith,an adjusting screw for adjusting the position of the spring, an electriccontact screw for making electric contact with said spring, and anelectrically operated impulse means controlled thru said contact andadapted to flex the spring a definite amount, the contact screw andimpulse'means being sb arranged that as the spring swings toward them itwill first make electric contact with the contact screw, after which theresulting action of the impulse means against the spring will break theelectric contact at the sprin and deliver a power impulse to said timeetermining element.

3. In a time keeping mechanism, the combination of a time determiningelement having a periodic motion, a spring attached thereto so as tooscillate therewith, an adjusting screw for adjusting the position ofthe spring, an electric contact screw for making electric contact withsaid spring, and an electrically operated impulse means controlled thrusaid contact and adapted to flex the spring adefinite amount, theadjusting screw, contact screw, and impulse means being so an rangedthat as thespring swings toward them screw for adjusting the position ofthe spring, an electric contact screw for making electric contact withsaid spring, and an electrically operated impulse means controlled thrusaid contact and adapted to flex the spring a definite amount, thecontact screw and impulse means being so arranged that as the s ringswings toward them. it will first make e ectric contact with the contactscrew, after which the resulting action of the impulse means will breakthe electric contact and deliver a power impulse to said time determinin element, the impulse means being re tamed in position to transmitsaid ower impulse thru frictional contact with t e spring.

5. In a time keeping mechanism, the combination of an electro-magneticdevice having a movable armature, a cam operated by said armature, alever operated by said cam, an impulse member operated by said lever, aspring, said impulse member being arranged to give substantially uniformimpulses to said spring regardless of moderate variations in the travelof said impulse member, an electric contact operated by said spring andadapted to be opened by the action of the impulse member against thespring, whereby the electro-magnetic device is periodically energized todeliver impulses to the spring, a crutch attached to said spring, and apendulum element. in said crutch, whereby the spring may drive thependulum.

6. In a time keeping mechanism, the combination of 'an electro-magneticdevice having a movable armature, a cam operated by said armature, alever operated by said cam, an impulse member operated by said lever, aspring, said impulse member being arranged to give substantially uniformimpulses to said spring regardless of moderate variations in the travelof said impulse member, an electric contact operated by said spring andadapted to be opened by the action of the impulse member against thespring, whereby the electro-magnetic device is periodically energized todeliver impulses to the spring, a yieldable crutch attached to saidspring, said crutch being arranged to transmit any normal driving forcewithout yielding, but being proportioned to yield in the case ofexcessive forces, and a pendulum element in said crutch, whereby thespring may drive the pendulum.

7. In a time keeping mechanism, the combination of an electro-magneticdevice having a movable armature, a cam operated by said armature, alever operated by said cam, an impulse member operated by said lever, aspring, said impulse member being arranged to give substantially uniformimpulses to said spring regardless of moderate variations in the travelof said impulse member, an electric contact operated by said spring andadapted to be opened by the action of the impulse member against thespring, whereby the electro-magnetic device is periodically energized todeliver impulses to the sprin said spring also serving as a conductor inthe cuit of the electro-magnetic means, a yieldable crutch attached tosaid spring, said crutch being arranged to transmit any normal drivingforce without yielding, but being prortioned to yield in the case ofexcessive orces and a pendulum element in said crutch, whereby thespring may drive the pendulum.

8. In timekee ing mechanism, an oscillating time determining elementhaving periodic motion, a 3 ring arm operatively connected to and oscilating in synchronism with said element, an electric circuit, includingan electromagnet, rendered efiective by said arm as said arm approachesits limit of oscillation in one direction, and means operated by saidelectromagnet when said circuit is rendered efiective for flexing saidarm a short distance in the opposite direction from which it was movingwhen said circuit was rendered effective, and thereby rendering saidcircuit ineffective, whereby said arm will then exert a yieldingresilient stress on said element urging it towards the o posite limit ofits movement, said means or flexing .the arm being yieldingly urged in adirection to re-. lease said arm and into normal ineffective position,and said arm being operable upon said means to hold the latter againstreturn to normal ineffective position until the arm is substantiallyunfiexed due to its movement in the opposite direction with saidelement.

9. In a timekeeping mechanism, an oscillating time determining elementhaving periodic motion, a member resiliently and operatively connectedto and oscillating in synchronism with said'element, an electric circuitrendered efiective by said member as said member aproaches one limit ofoscillation, and including electro-magnetic means, impulse meansoperable by said electro-magneticmeans for forcing said member in theopposite direction from which it was moving when said circuit wasrendered efiective, and rendering said circuit ineffective, whereby saidmember will then exert a yieldingly resilient stress on said elementurging it towards the opposite limit of its movement, saidelectro-magnetic means being urged in a direction to releasesaid'impulse means when said circuit is rendered ineffective, and saidimpulse means and said member cooperating with one another to maintainsaid circuit ineffective until the stress of said member on said elementis approximately nil.

III

Ill

.10. In timekeeping mechanism, an oscillating time determining elementhaving periodic nausea said element in the opposite directim and holdinsaid circuit inefiective until the spring as moved out of a position inwhich it would render said circuit effective.

11. In timekeeping mechanism, an oscillating time determining elementhaving periodic motion, a member resiliently connected to andoscillating in synchronism .with said element, and a ower devicerendered effective by said mem r as said member approaches one limit ofits movement for moving said member immediately into a predeterminedposition in which said member exerts a resilient stress on said elementtending to move it in the opposite direction and temporarilyincapacitating said power device against further movement after saidmember reaches said position until said element has reached apredetermined point in its movement in the opposite direction. I

12. In timekeeping mechanism, an oscillating time determining elementhaving periodic motion, a spring, arm operatively connected to andoscillating in synchronism with said element, an electric circuitincludin contact meansclosed by engagement therewith of the free ends ofsaid arm as said element and arm approach their normal limit ofoscillation in one direction, and means rendered effective by saidcircuit for flexing immediately said spring arm into circuit 0 ningposition and placing a-stress on said e ement tendin vvto force it inthe opposite direction, sai

means holding said spring arm in a position in which sa1d circuit isinefiective until'sald arm has been moved out of circuit closingposition by the return oscillation of said element,

whereby said element will receive riodic impulses for maintaining it inoscillation and said circuit will be closed only for a relatively shortfraction ofthe oscillatory period of said element.

13. In a timekeeping mechanism, the combination of a time determiningelement having a periodic motion, a spring attached thereto so as tooscillate therewith, and an impulse member adapted to-be swung in an arcterminating substantially tangent to said spring, and retained in thatposition by friction while flexing said spring.

14. In a timekeeping mechanism, the combination of a time determiningelement having a periodic motion, means for delivering smallperiodicjmpulses thereto comprising a spring attached to said timedetermining elementso as to oscillate'therewith, and an impulse memberadapted to engage said spring with a sliding motion of diminishingangularity relative thereto, so that the movement of the point ofcontact of said impulse member will approach parallelism to the springtoward the end of the impulse, whereby a substantially definite impulseis given to the spring and time determining element regardless of minorvariations in the stroke of said impulse member.

15. In timekeeping mechanism, an oscillating time determining elementhaving periodic motion, a spring arm operatively connected to andoscillating in synchronism with said element, an electriccircuit,including an electromagnet, rendered effective by said arm as said. armapproaches its limit of oscillation in one direction, means operated bsaid electromagnet when said circuit is ren ered eflective for flexinsaid arm a short distance in the opposite rection from which it wasmoving when said circuit was rendered effective, and thereby renderingsaid circuit ineffective, whereby said arm will then exert a yieldingresilient stress on said element urgmg it towards the opposite limit ofits movement, said means for flexing the arm bein yieldingly urged in adirection to release said arm an into normal inefi'ective position, andsaid arm being operable upon said means to hold the latter againstreturn to normal ineffective position until the arm is substantiallyunflexed due to its movement in the opposite direction with saidelement, and an abutment movable with said element in fixed relationthereto, anda ainst which said arm is resiliently urged w en released,whereby the normal position of said arm relatively to said element willbe definitely fixed.

16. In timekeeping mechanism, an oscillating time determining elementhaving periodic motion, a spring arm operatively connected to andoscillatin in synchronism with said element, an electric circuit,including an electromagnet, rendered effective by sa1d arm as said armapproaches its limit of oscillation in one direction, means operated bysaid electromagnetic when said circuit is rendered effective for flexingsaid arm a short distance in the opposite direction from which it wasmoving when said circuit was rendered effective, and thereby renderingsaid circuit inefl'ective, whereby said arm will then exert a yieldingresilient stress on said element urging it towards the opposite limit ofits movement, said means for flexing the arm being (Yieldingly urged ina direction to release sai arm and into normal ineffective position, andsaid arm being operable upon said means to hold the latter againstreturn to normal ineffective position until the arm is substantiallyunflexed due to its movement in the opposite direction with saidelement, and an abutment movable with said element and adjustable inrelation thereto, and against which said arm is resiliently urged whenreleased, whereby the normal position of said arm relatively to saidelement may be selectively and adjustably determined.

17. In timekeeping mechanism, an oscillating time determining elementhaving periodic motion, a spring operatively connected thereto andoscillating synchronously tion and holding said circuit ine electriccircuit rendered efiective by said ring as said spring approaches onelimit of its oscillation, means controlled by said circuit for stressingsaid s ring in the opposite direction to exert a resi ient impulse onsaid element in the o posite direction and holding said circuit ineective until the spring has moved out of a position in which it wouldrender said circuit efiective, and an abutment oscillating in fixedrelation to said element and a ainst which said spring is yieldinglyurge when free from said stressing means.

18. In timekeeping mechanism, an oscillating time determming elementhaving periodic motion, a spring operatively connected thereto-andoscillating synchronously therewith, an electric circuit renderedefiective by said spring as said spring approaches one limit of itsoscillation, means controlled by said circuit for stressing said s ringin the opposite direction to exert a resi ient impulse on said elementin the opposite direcective until the spring has moved out of a positionin which it would render said circuit efiective, and an abutmentoscillating in fixed relation to said element but adjustable in relationthereto and against which said spring is yieldingly urged when free fromsaid stressing means.

19. In timekeeping mechanism, an oscillating time determining elementhaving therewith, an

periodic motion, a spring arm operatively' connected to and oscillatingin synchronism with said element and adjustable relatively to saidelement in the direction of oscillation, an electric circuit includingcontact means v closed by engagement therewith of the free ends of saidarm as said element and arm approach their normal limit of oscillationin one direction, and means rendered efiective by said circuit forflexing immediately said spring arm into circuit opening position andplacing a stress on said element tending to force 1t in the oppositedirection, said means holding said'spring arm in a position in whichsaid circuit is ine ective until said arm has been moved out of circuitclosing position by the return oscillations of said element, wherebysaid element will receive periodic im ulses for maintaining it inoscillation an said circuit will be closed only for a relatively shortfraction of the oscillatory period of said element.

In witness whereof I have hereunto set my hand this 1st day of April,1927.

ARTHUR F. POOLE.

